Rashid Z Khan

Four genes predict high risk of progression from smoldering to symptomatic multiple myeloma (SWOG S0120)

Multiple myeloma is preceded by an asymptomatic phase, comprising monoclonal gammopathy of uncertain significance and smoldering myeloma. Compared to the former, smoldering myeloma has a higher and non-uniform rate of progression to clinical myeloma, reflecting a subset of patients with higher risk. We evaluated the gene expression profile of smoldering myeloma plasma cells among 105 patients enrolled in a prospective observational trial at our institution, with a view to identifying a high-risk signature. Baseline clinical, bone marrow, cytogenetic and radiologic data were evaluated for their potential to predict time to therapy for symptomatic myeloma. A gene signature derived from four genes, at an optimal binary cut-point of 9.28, identified 14 patients (13%) with a 2-year therapy risk of 85.7%. Conversely, a low four-gene score (<9.28) combined with baseline monoclonal protein <3 g/dL and albumin ≥3.5 g/dL identified 61 patients with low-risk smoldering myeloma with a 5.0% chance of progression at 2 years. The top 40 probe sets showed concordance with indices of chromosome instability. These data demonstrate high discriminatory power of a gene-based assay and suggest a role for dysregulation of mitotic checkpoints in the context of genomic instability as a hallmark of high-risk smoldering myeloma.

Renal insufficiency retains adverse prognostic implications despite renal function improvement following Total Therapy for newly diagnosed multiple myeloma

Renal insufficiency (RI) is a frequent complication of multiple myeloma (MM) with negative consequences for patient survival. The improved clinical outcome with successive Total Therapy (TT) protocols was limited to patients without RI. We therefore performed a retrospective analysis of overall survival, progression-free survival and time to progression (TTP) of patients enrolled in TT2 and TT3 in relationship to RI present at baseline and pre-transplant. Glomerular filtration rate was graded in four renal classes (RCs), RC1–RC4 (RC1 ⩾90 ml/min/1.73 m2, RC2 60–89 ml/min/1.73 m2, RC3 30–59 ml/min/1.73 m2 and RC4 <30 ml/min/1.73 m2). RC1–3 had comparable clinical outcomes while RC4 was deleterious, even after improvement to better RC after transplant. Among the 85% of patients with gene expression profiling defined low-risk MM, Cox regression modeling of baseline and pre-transplant features, which also took into consideration RC improvement and MM complete response (CR), identified the presence of metaphase cytogenetic abnormalities and baseline RC4 as independent variables linked to inferior TTP post-transplant, while MM CR reduced the risk of progression and TTP by more than 60%. Failure to improve clinical outcomes despite RI improvement suggested MM-related causes. Although distinguishing RC4 from RC<4, 46 gene probes bore no apparent relationship to MM biology or survival.

Dose-dense and less dose-intense Total Therapy 5 for gene expression profiling-defined high-risk multiple myeloma

Multiple myeloma (MM) is a heterogeneous disease with high-risk patients progressing rapidly despite treatment. Various definitions of high-risk MM are used and we reported that gene expression profile (GEP)-defined high risk was a major predictor of relapse. In spite of our best efforts, the majority of GEP70 high-risk patients relapse and we have noted higher relapse rates during drug-free intervals. This prompted us to explore the concept of less intense drug dosing with shorter intervals between courses with the aim of preventing inter-course relapse. Here we report the outcome of the Total Therapy 5 trial, where this concept was tested. This regimen effectively reduced early mortality and relapse but failed to improve progression-free survival and overall survival due to relapse early during maintenance.

Adverse metaphase cytogenetics can be overcome by adding bortezomib and thalidomide to fractionated melphalan transplants

Purpose: To determine whether a reduction in the intensity of Total Therapy (TT) reduces toxicity and maintains efficacy. Experimental Design: A total of 289 patients with gene expression profiling (GEP70)-defined low-risk multiple myeloma were randomized between a standard arm (TT4-S) and a light arm (TT4-L). TT4-L employed one instead of two inductions and consolidations. To compensate for potential loss of efficacy of TT4-L, bortezomib and thalidomide were added to fractionated melphalan 50 mg/m2/d for 4 days. Results: Grade ≥3 toxicities and treatment-related mortalities were not reduced in TT4-L. Complete response (CR) rates were virtually identical (P = 0.2; TT4-S, 59%; TT4-L, 61% at 2 years), although CR duration was superior with TT4-S (P = 0.05; TT4-S, 87%; TT4-L, 81% at 2 years). With a median follow-up of 4.5 years, there was no difference in overall survival (OS) and progression-free survival (PFS). Whereas metaphase cytogenetic abnormalities (CAs) tended to be an adverse feature in TT4-S, as with predecessor TT trials, the reverse applied to TT4-L. Employing historical TT3a as training and TT3b as test set, 51 gene probes (GEP51) significantly differentiated the presence and absence of CA (q < 0.0001), seven of which function in DNA replication, recombination, and repair. Applying the GEP51 model to clinical outcomes, OS and PFS were significantly inferior with GEP51/CA in TT4-S; such a difference was not observed in TT4-L. Conclusions: We identified a prognostic CA-linked GEP51 signature, the adversity of which could be overcome by potentially synergizing anti–multiple myeloma effects of melphalan and bortezomib. These exploratory findings require confirmation in a prospective randomized trial. Clin Cancer Res; 23(11); 2665–72. ©2016 AACR.

Flow cytometry defined cytoplasmic immunoglobulin index is a major prognostic factor for progression of asymptomatic monoclonal gammopathies to multiple myeloma (subset analysis of SWOG S0120).

Multiple myeloma (MM) is a clonal plasma cell (PC) disorder characterized by end organ damage that is in turn characterized by CRAB criteria (calcium and creatinine elevation, anemia and bone lesions).1 It is commonly accepted that nearly all cases of MM are preceded by a clinically benign phase of monoclonal gammopathy of undetermined significance (MGUS) that evolves through a stage of smoldering multiple myeloma (SMM) without end organ damage,2 collectively referred to as asymptomatic monoclonal gammopathies (AMG).3 Although traditionally SMM is considered more prone to MM progression than MGUS, additional variables, such as involved-to-uninvolved free light-chain ratio4 and magnetic resonance imaging-defined focal lesion number and size,5 have been linked to progression to MM and form the basis for the newest International Myeloma Working Group criteria for MM.6 As the treatment of MM has been greatly advanced, emphasis has been placed on identifying patients with AMG at high risk of progression to MM so that, with earlier treatment, end organ damage can be minimized.7 Many new high-risk variables have indeed been identified such as level of circulating plasma cells8 and gene expression profiling (GEP).9, 10 We have previously reported that two-parameter flow cytometry of DNA and cytoplasmic light-chain immunoglobulin (DNA/CIG) is highly predictive of progression-free and overall survival in newly diagnosed MM treated with Total Therapy.11 In the current subset analysis of S0120, we have investigated whether the DNA/CIG assay can also identify patients with AMG at high risk for progression to MM requiring therapy (time to therapy, TTT).12 Of 254 patients enrolled at the University of Arkansas in the observational SWOG S0120 protocol with AMG, 110 had evaluable DNA/CIG information and retained AMG status according to the revised International Myeloma Working Group criteria for MM.6 All patients underwent detailed clinical staging as previously reported.9, 10 DNA/CIG assay was performed on whole bone marrow aspirates along with metaphase cytogenetics and GEP of CD138+ purified PC.13 Imaging studies involved metastatic bone surveys and, in the majority of the cases, magnetic resonance imaging examination of the axial and appendicular skeleton. Details of the DNA/CIG method have been published elsewhere.14, 15 A technical modification of the assay was applied uniformly since August 2006. The assay is based on the two-parameter flow cytometry of cytoplasmic immunoglobulin and DNA of whole bone marrow aspirates. Single-cell suspensions were exposed to anti-light-chain reagents (Dako Kappa and Lambda light chain F(AB)2/FITC conjugated) and then counterstained for DNA with propidium iodide with the addition of RNase. To quantitate the cellular DNA content, DNA index (DI)16 was determined and calculated as the ratio of the mean for each light-chain-positive G0/1 DNA peak divided by the mean of the light-chain-negative diploid G0/1 peak on the X axis. A DI between 0.99 and 1.01 was referred to as diploid, while hyperdiploid implied DI>1.01 and hypodiploid DI<0.99. The excess of kappa- or lambda-positive cells identified the involved or light-chain-restricted (LCR) cell population, the percentage of which was calculated in relation to the total number of gated events. Among the LCR cell population, discrete populations of cells with different DI were identified, which we refer to from here on as DNA stem lines. The involved DNA stem line with the highest percentage was considered dominant. To quantitate the cytoplasmic immunoglobulin content of a light-chain-positive population, the cytoplasmic immunoglobulin index (CIg) was used and calculated from the ratio of the geometric mean of the Y axis (cytoplasmic immunoglobulin fluorescence intensity) for the light-chain-positive G0/1 peak divided by the Y axis geometric mean of the light-chain-negative diploid G0/1 population. The CIg of each distinct DNA stem line was calculated as explained above. Kaplan–Meier methods were used to generate survival distribution graphs, and comparisons were made employing the log-rank test. For continuous variables, the running log-rank method was applied for the calculation of optimal cutoff points. The R2 statistic was used to evaluate the predictive power of different models. Wilcoxon tests were used to compare the medians of continuous measurements between groups. The characteristics of the 110 patients lacking the revised International Myeloma Working Group criteria for MM are portrayed in Supplementary Table 1. The median follow-up time for the 110 patients was 4.8 years. Aneuploidy by DNA/CIG was evident in 64%, all of whom had hyperdiploid stem lines, while additional hypodiploid abnormalities were present in two cases. Low hemoglobin (<10 g/dl) pertained to only 4% (non-plasma cell dyscrasia-related reasons) while creatinine ⩾2 mg/dl was evident in one case due to hypertension-related nephrosclerosis. Metaphase cytogenetic abnormalities (CA) were documented in 16%, a GEP70 score⩾−0.26(ref. 3) pertained to 33% and a recently defined novel GEP4 score⩾9.28(ref. 17) to 12% of patients. We examined the TTT probability of AMG (Table 1). Optimal cutoff points were obtained for all continuous numerical values. We confirm other studies linking older age ⩾65 years, albumin 8.4 The presence of CA, GEP70- and GEP4- high-risk designations was strongly linked to inferior TTT. Among DNA/CIG-derived parameters, CIg 17 were both strongly linked to progression to MM. Other DNA/CIG variables associated with TTT included the presence of aneuploidy and the presence of ⩾2 DNA stem lines (Figure 1). The 26 patients with CIg 17 present in 20 patients conferred a 2-year MM progression rate of 60% versus 9% among the 90 with lower (Figure 1b). Consideration of both DNA/CIG features identified 14 patients displaying two high-risk features with 2-year TTT of 71.4% as opposed to 5.1% in 78 patients with only favorable features, while the presence of one adverse variable present in 18 patients was associated with a 2-year TTT probability of approximately 34% (Figure 1c). Figure 1 Kaplan–Meier plots for the time to progression from AMG to MM requiring therapy according to: CIg, (a) total LCR%, (b) the combination of CIg and total LCR% (c) and the combination of CIg and total LCR% for the SMM population ... Table 1 Cox regression for time to progression to MM In the multivariate model, serum-M⩾3 g/dl, CIg 17% independently conferred adverse outcomes (Table 1). All three parameters combined provided for a high R2 value of 0.861, implying that TTT probability could be accounted for in 86% (Supplementary Table 2). In comparison, the classical criteria of bone marrow plasmacytosis ⩾10% and serum-M⩾3 g/dl had a lower cumulative R2 of 0.632. When only the sub-population of SMM (80 patients; Supplementary Table 3) was considered, DNA/CIG-derived variables retained their statistical significance (Supplementary Table 4). Both LCR>17% and CIg 17% and serum-M⩾3 g/dl; albumin<3.5 g/dl and B2M⩾3.5 mg/l also conferred higher TTT probability for a R2 of 0.862 (Supplementary Tables 4 and 5). The inclusion of GEP variables, available in a subset of 61 patients, identified GEP-4 as a significant variable, dispelling CIg and B2M from the model (R2=0.895; Supplementary Tables 4 and 6). CIg is a measure of plasma cell immunoglobulin production.15 We therefore examined CIg values in patients with MGUS and SMM (both from the S0120 trial), and in newly diagnosed MM patients accrued to Total Therapy 3b.18 Median CIg values declined progressively with the transition from MGUS to SMM and later to MM (10.5 versus 5.6 versus 3.3, P<0.001; Supplementary Figure 1a). To exclude the possibility that the difference in CIg reflects the decreasing percentage of highly secreting normal plasma cells with the evolution of plasma cell dyscrasias,19, 20 the analysis was repeated for strictly aneuploid cases. Again, the evolution from MGUS to SMM to MM was characterized by a progressively lower CIg (16.0 versus 9.1 versus 3.5, P<0.0001; Supplementary Figure 1b). In summary, DNA/CIG offers powerful prognostic information for AMG even in the era of genomic profiling. While LCR% reflects tumor burden, the finding of progressively decreasing CIg with the evolution of plasma cell dyscrasias in this single institution subset analysis of S0120 is novel. It provides evidence that the progression of plasma cell dyscrasias is accompanied by a progressive decline in immunoglobulin production capacity.

The flow cytometry-defined light chain cytoplasmic immunoglobulin index and an associated 12-gene expression signature are independent prognostic factors in multiple myeloma

As part of Total Therapy (TT) 3b, baseline marrow aspirates were subjected to two-color flow cytometry of nuclear DNA content and cytoplasmic immunoglobulin (DNA/CIG) as well as plasma cell gene expression profiling (GEP). DNA/CIG-derived parameters, GEP and standard clinical variables were examined for their effects on overall survival (OS) and progression-free survival (PFS). Among DNA/CIG parameters, the percentage of the light chain-restricted (LCR) cells and their cytoplasmic immunoglobulin index (CIg) were linked to poor outcome. In the absence of GEP data, low CIg <2.8, albumin <3.5 g/dl and age ⩾65 years were significantly associated with inferior OS and PFS. When GEP information was included, low CIg survived the model along with GEP70-defined high risk and low albumin. Low CIg was linked to beta-2-microglobulin >5.5 mg/l, a percentage of LCR cells exceeding 50%, C-reactive protein ⩾8 mg/l and GEP-derived high centrosome index. Further analysis revealed an association of low CIg with 12 gene probes implicated in cell cycle regulation, differentiation and drug transportation from which a risk score was developed in TT3b that held prognostic significance also in TT3a, TT2 and HOVON trials, thus validating its general applicability. Low CIg is a powerful new prognostic variable and has identified potentially drug-able targets.

CA-125 secreting IgG kappa multiple myeloma.

currently on hemodialysis three times per week. His baseline liver iron concentration estimated by R2 MRI was 25.8 mg/g dry weight at baseline before administration of deferasirox. He was started on deferasirox at a dose of 15 mg/kg/day with the dose gradually increased to 25 mg/kg/day. Since being started on deferasirox, the ferritin level has steadily decreased from 3,846 to 1,447 ng/mL over the course of 11 months. He had an episode of asymptomatic hypocalcemia 6 months after initiation of treatment with the level reaching 6.5 mmol/L and subsequently improving to 8.4 mmol/L in 1 month without any intervention. Patient B is a 59-year-old woman with transfusion-dependent b-thalassemia intermedia. Her baseline liver iron concentration estimated by R2 MRI was 26.1 mg/g dry weight at baseline before administration of deferasirox. She was started on deferasirox 15 mg/kg/ day and the dose was gradually increased to 25 mg/kg/day. Her ferritin levels have shown only mild improvement going down from 4,300 to 4,120 ng/mL over the course of 8 months before going back up to 4,479 ng/mL 11 months after initiation of treatment. She did not have any episodes of hypocalcemia while on treatment. Deferasirox and its metabolites are primarily excreted through the fecal route (84% of the dose), while renal excretion of deferasirox and its metabolites is minimal (8% of the dose) [6]. Despite this, ESRD profoundly affects deferasirox pharmacokinetics. Maker et al. reported a nearly 10-fold increase in mean plasma concentration for deferasirox at a dose of 15 mg/kg compared with 10 mg/kg in their hemodialysis cohort suggesting that uremia may reduce fecal excretion or enhance intestinal reabsorption of deferasirox resulting in higher than predicted plasma levels [7]. In 2008, Yusuf et al. were the first to report the use of deferasirox in a female patient on peritoneal dialysis secondary to sickle cell nephropathy for 6 months [4]. At 20 mg/kg/day, treatment with deferasirox was associated with a decrease in serum ferritin but was discontinued due to symptomatic hypocalcemia. This was the first time severe symptomatic hypocalcemia was reported with deferasirox use. In another report by Yusuf et al., a male patient with paroxysmal nocturnal hemoglobinuria on hemodialysis received deferasirox at doses ranging between 15 and 30 mg/kg/day [3]. There were no significant complications and an improvement in serum ferritin was achieved. Hiraga et al. reported the safe treatment of a male patient with aplastic anemia who is on hemodialysis with deferasirox at a dose of 20 mg/kg/day [5]. Chen et al. retrospectively reviewed the data pertaining to eight hemodialysis patients who were treated with deferasirox for iron overload associated with transfusiondependent anemia of renal disease [6]. A dose of 15 mg/kg/day reduced the iron burden. No serious adverse events were observed and none of the patients required drug discontinuation [7]. Deferasirox was also safely used in our two patients. No adverse events were noted except for asymptomatic hypocalcemia in one of the patients (Table I). The doses we reached in our patients (up to 25 mg/kg/day) were higher than those reported in the literature before. Deferasirox appears to be safe to use in ESRD patients up to a dose of 25 mg/kg/day. Therefore, deferasirox seems to hold a promise in managing iron overload in thalassemia patients with ESRD especially in the light of the lack of alternative agents.